package nework;

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.SocketException;

/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: GodK
 * Date: 2024-08-08
 * Time: 21:53
 */
public class UdpEchoServer {
    private DatagramSocket socket = null;
    public UdpEchoServer(int port) throws SocketException {
        socket = new DatagramSocket(port);
    }
    public void start() throws IOException {
        System.out.println("服务器启动!");
        while(true){
            //读取并解析
            DatagramPacket requestPacket = new DatagramPacket(new byte[4096],4096);
            socket.receive(requestPacket);
            //转换成字符串
            String request = new String(requestPacket.getData(),0,requestPacket.getLength());
            //响应就是请求
            String response = process(request);
            //响应写回到客户端
            DatagramPacket responsePacket = new DatagramPacket(response.getBytes(),response.getBytes().length,
                    requestPacket.getSocketAddress());
            socket.send(responsePacket);
            //日志打印
            System.out.printf("[%s:%d] req=%s, resp=%s\n", requestPacket.getAddress(), requestPacket.getPort(),
                    request, response);
        }
    }
    public String process(String request) {
        return request;
    }
    public static void main(String[] args) throws IOException {
        UdpEchoServer server = new UdpEchoServer(9090);
        server.start();
    }
}
